North Korea test-launches 2 ballistic missiles, after end of new US-South Korea-Japan drill

North Korea test-fired two ballistic missile Monday, South Korea's military said, a day after the North vowed "offensive and overwhelming" responses to a new US military drill with South Korea and Japan. The Joint Chiefs of Staff said the missiles were launched 10 minutes apart in a northeastern direction from the town of Jangyon in southeastern North Korea.

It said the first missile flew 600 kilometres (370 miles) and the second missile 120 kilometres (75 miles), but didn't say where they landed. North Korea typically test-fires missiles toward its eastern waters, but the second missile's flight distance was too short to reach those waters.

South Korean media said an unidentified South Korean military source reported that it was highly likely the second missile crashed in an inland area of the North. Possible damages on the North's ground weren't immediately reported.

The reports said the first missile landed in the waters off the North's eastern city of Chongjin.

South Korea's Joint Chiefs of Staff, which did not comment on the media reports, said South Korea maintains a firm readiness to repel any provocations by North Korea in conjunctions with the military alliance with the United States.

The launch came two days after South Korea, the US and Japan ended their new multidomain trilateral drills in the region.

In recent years, the three countries have been expanding their trilateral security partnership to better cope with North Korea's evolving nuclear threats and China's increasing assertiveness in the region.

The "Freedom Edge" drill was meant to increase the sophistication of previous exercises with simultaneous air and naval drills geared toward improving joint ballistic-missile defence, anti-submarine warfare, surveillance and other skills and capabilities. The three-day drill involved a US aircraft carrier as well as destroyers, fighter jets and helicopters from the three countries.

On Sunday, North Korea's Foreign Ministry issued a lengthy statement strongly denouncing the "Freedom Edge" drill, calling the US-South Korea-Japan partnership an Asian version of NATO. It said the drill openly destroyed the security environment on the Korean Peninsula and contained a US intention to lay siege to China and exert pressure on Russia.

The statement said North Korea will "firmly defend the sovereignty, security and interests of the state and peace in the region through offensive and overwhelming countermeasures."

Monday's launch was the North's first weapons firing in five days.

On Wednesday, North Korea launched what it called a multiwarhead missile in the first known launch of a developmental, advanced weapon meant to defeat US and South Korean missile defences. North Korea said the launch was successful, but South Korea dismissed the North's claim as deception to cover up a failed launch.

In recent weeks, North Korea has floated numerous trash-carrying balloons toward South Korea in what it has described as a tit-for-tat response to South Korean activists sending political leaflets via their own balloons. Last month, North Korea and Russia also struck a deal vowing mutual defense assistance if either is attacked, a major defence pact that raised worries that it could embolden Kim to launch more provocations at South Korea.

Meanwhile, North Korea opened a key ruling party meeting Friday to determine what it called "important, immediate issues" related to works to further enhance Korean-style socialism.